The synthesis of sulfone compounds and in particular beta-aminosulfone compounds is of interest because these compounds may be particularly useful in the preparation of molecules with a potential for biological activities such as alfa-amino acids, uridines, adenosines, beta-lactams, etc.
The synthesis of sulfone compounds and in particular beta-aminosulfone compounds may thus provide useful intermediates for the synthesis of anti-inflammatory agents, preferably active for the treatment of psoriasis or psoriatic arthritis such as Apremilast.
Patent application WO 00/025777 A1 describes the synthesis of racemic beta-aminosulfone (1) and derivatives thereof, as illustrated in Scheme 1 below.

However, the overall synthetic route is characterized by several steps and low yield and selectivity, and uses expensive as well as hazardous materials, such as BF3 Et2O, very difficult to handle at the industrial scale.
Patent application WO 2010/030345 A2 describes the synthesis of racemic beta-aminosulfone (1) and derivatives thereof, as illustrated in the overall Scheme 2 below.

Although characterized by higher yields, this process too requires several steps to build the main molecular skeleton and using hydroxylamine could be a hazardous drawback anyway. Interestingly, the racemic form of beta-aminosulfone (1) can be prepared according to the overall route illustrated in Scheme 3 depicted below.

Oxidation of (4) to (5) can be carried out according to methods commonly known in the field of organic chemistry. The obtained carboxylic acid (5) is then converted into the corresponding methyl ester (6), in its turn transformed into keto-sulfone (7) following the teachings of patent application WO 2013/126360 A2. Finally, (7) is converted into the desired racemic beta-aminosulfone via reduction of imine (8) in accordance with commonly known methods. Patent application CN 105348172 A describes the synthesis of racemic beta-aminosulfone (1), as illustrated in the overall Scheme 4 below.

Although characterized by higher yields, once again these processes do not provide short and simple processes for preparing compound (1). Alternative methods for the preparation of racemic beta-aminosulfone (1), particularly for manufacturing large scale production, are thus desirable.
Object of the present invention is to provide a short, simple, cost-effective, environmentally friendly and industrially suitable synthetic process for preparing racemic beta-aminosulfone intermediate (1) which starts from simple and commercially available reagents.